#Circadian rhythm

The optical shield that protects you from the artificial light wrecking your biology

Why the sunlight you meet on waking is the biochemical signal your body needs to oxidise fat efficiently

How UVB radiation switches on receptors that reinforce the intestinal barrier and tune immunity

How our cells work as electrical batteries tuned to the photoperiod and to solar radiation

How the solar spectra of dawn, noon, and dusk coordinate cell biology and vitamin D